Changeable luminous display



July 28, 1931. F. Ho'rcHNER CHANGEABLE LUMINOUS DISPLAY Filed April 6,1951 2 Sheets-Sheet 1 2 Sheets-Sheet 2 fnuen''or F. HOTCHNER CHANGEABLELUMINOUS DISPLAY Filed April 6, 1931 July 28, 1931.

'Patented July 28, 1931 PATENT OFFICE FRED HOTCHNER, OF LOS ANGELES,CALIFORNIA CHANGEALBLE LUMINOUS DISPLAY Application led April 6,

This invention relates to a changeable luminous display and the objectthereof is to provide an illuminated display having means to write atwill upon a display surface thereof any desired copy and eradicate thesame without using any paints, pigments, writing material, mechanicalcontrivances or special tools.

I have discovered that if light is passed thru a body of glass or anyother suitable light transmitting material at such an angle that amaterial portion thereof is reflected back into the body of glass at asurface thereof, an illuminated display may be produced by positioningclose to that surface a sheet of translucent material having a surfaceadhesive to the surface of the glass. Thus upon pressing down anyportion of the sheet until an intimate contact is made with the glass,

light will escape from the glass at such portions thus rendering suchportions luminous to the eye.

The most suitable way of introducing the light into the body is thru anedge thereof.

In a previously filed co-pending application of mine No. 384,172, datedAugust 7, 1929 I have disclosed a manner of producing a body of lighttransmitting material with a discharge passageway formed thru the samein 3o which an ionization conductor is placed and illuminated by thepassage of current. Such a device is very suitable for the main elementin this invention. However the invention may be practiced in numerousother manners,

such for instance as by utilizing a sheet lof glass with a luminous tubepositioned around the edge thereof so that a material portion of theradiation therefrom enters the glass at such an angle as to be reflectedfrom the sur- 40 face to be used for changeable display purposes.

Among the objects of the invention is the production of a changeablesign of the general type described in which no writingmaterial need beused; the production of a changeable sign in which the copy may beinstantly changed by the simple operation o stripping up the displaysheet; the production of a sign of the general type described which maybe made either as a single or a 1931. Serial No. 528,032.

double faced sign; and the production of a sign of the general typedescribed in which the source of illumination is utilized as part of thevisible display.

It is a further object of the invention to produce a sign of the generaltype described in which a Very high degree of the total radiation fromthe illuminating tube is effectively directed into the changeabledisplay section.

'IT is a further object of one form of the invention to direct thedispersed light at the characters substantially entirely to one side ofthe plane of contact with the glass in order to double the intensity ofthe sign.

Further objects will be apparent from the y accompanying drawings andthe description below, it being understood that the invention is notlimited to the particular embodiments shown but may be variouslyembodied within the purview of the claims which are to be limited onlyby the prior art and the specific limitations embodied therein.

An embodiment of the invention is shown in the accompanying drawings inwhich Figure 1 is a front view of a sign made according to thisinvention and Figure 2 is a cross section of the same taken on the line2-2. Figure 3 is an enlarged cross section of a portion of the glassbody and the display sheet to illustrate the relative proportion of theelements of the changeable portion more accurately than is shown inFigure 2 in which the degree of depression of the copy portions of thedisplay sheet is exaggerated for the purposes of illustration.

Figure 4 is a front view of a modified form of the invention.

Figure 5 is a side Vview of the same.

Figure 6 is an enlarged section of a portion of the same.

Figure 7 is a greatly enlarged section of the display sheet used in thesign shown in Figure 4.

Numeral 1 indicates a body of glass having formed therethru a dischargepassage indif cated by 2. Any suitable method of fabrication may be usedto form this device. The particular illustrated device may be madeaccording to the disclosure of my application No. 384,172 according towhich the body 1 is formed of two sheets of glass 3 and 4 having grooves5 and 6 which upon being juxtaposed form the passage 2. Electrodeterminals 9 and 10 are provided at the ends of the passage and lead inconductors 11 and 12 connect the same to the terminal contacts 13 and14.

The display sheets 15 and 16 are positioned on the surfaces 17 and 18 ofthe glass body and are preferably permanently secured thereto along theedges 19 and 20. The lower edges 21 and 22 are loose and the sheets maybe raised and peeled away from the surfaces as shown by the dotted linesin Figure 2.

The inside surfaces of the display sheets indicated by 23 and 24 are sotreated that upon being pressed down onto the glass an intimate contactis formed therewith thru which light may escape from the body of glassand render the display sheet luminous to the eye at such places. I havefound that a soft rubber coating on the display sheet serves thispurpose admirably and also serves to retain the depressed portions ofthe display sheet in Contact with the glass. It is desirable that thelight be diffused or dispersed at the depressed places. This may be doneby providing a translucent display sheet or the property of scattering`the light may be provided by the coating material.

In Figure 2 a finger is shown in dotted lines illustrating a manner inwhich copy may be written on the device. Thus at the place indicated by25 copy is being formed. At the places indicated by 26 on the same sideand by 27 and 28 on the reverse side copy has already been formed andthe display sheet is in contact with the glass. The portions indicatedby 29, 30, 31, 32, 33 and 34 are out of contact with the glass and henceto the eye these portions are relatively dark as the radiation incidentupon the glass surface adjacent thereto is returned into the glass bodyby total reflection. I have shown spaces indicated by 35, 36, 37, 38, 39and 40 at these places, but it is to be understood that the spaces shownare exaggerated as is also the degree of depression of the copy areas ofthe display sheet- Actually the two may be in contact at these placesbut as long as the contact is not sufliciently intimate to provide a.substantial continuity of matter permeable to light the effect is thesame as tho they were separated a material distance. To eradicate thecopy the lower edges of the sheets are lifted and stripped of the glassas shown by the dot-ted lines in Figure 2.

In Figure 3 I have shown on an enlarged scale a section of the glass andthe display sheet to more correctly illustrate the condition of the two.The sheet indicated by 15 consists of the flexible body 42 which may beof such material as parchment, and the layer of adhesive material 43which may be soft rubber.` The portion between the arrows A-A is incontact with the glass suiliciently intimate to render it luminous.

The path of a ray of light indicated by C-C is shown reflected back froma portion of the surface of the glass at which the rubber is inindifferent contact or slightly separated therefrom. This is alsoshownvfor another ray by D--D. However a ray indicated by E falls upon aportion of the surface at Awhich intimate-contact has been made and isdispersed, a material portion of the light being scattered out into theair as shown by F and constituting that portion of the light which.serves to render the copy luminous. It is to be understood however thatthe dispersed lightv is scattered in all directions from each point ofdispersion and hence someof the light at the illuminated copy isreturned into the body of glass.

In Figures 4, 5, 6 and 7 'I show how a single faced sign of very highefliciency may be made according to this invention.

The main element in this case may be made as before with the dischargepassage formed Within the vglass body. However I have shown analternative construction. Numeral 50 indicates a sheet of glass having aluminous tube 51 around the edge thereof serving as a border and thesource of radiation for the changeable copy. Any suitable mounting maybe used to support the same in a finished sign and provide the electricconnections to the electrode terminals 52 and 53. The dis-` play sheet54 in this case is on the reverse side from that exposed directly toView and indicated by 55 and the dispersed radiation reaches the eyeafter passing across the glass body.

The display sheet is preferably secured at one edge to the glass sheetas shown at 56 and the lower edge left so that it can be lifted andstripped oli' to eradicate the copy. In Figure 6 the portion indicatedby the arrows G-G is in contact with the glass suiliciently intimate tobecome luminous. The path of a ray which falls upon a surface unaffectedby the display sheet is shown by H-H. The path of a ray which falls oncopy space is shown by K-K. The ray in this case is dispersed anddirected entirely in one direction from the display sheet.

This is indicated at M. It will be noted that the light which delineatesthe copy to the eye passes thru the body of glass to the observer. Thustwice the elfective illumination is directed to view. It will also bereadily seen that there is a certain percentage of these redirected rayswhich leave the point of dispersion at an angle so sharp that they areagain-reflected into the body of the glass at the exposed surface of theglass. However such rays are those whose angle is beyond the usefulrange for vdisplay purposes and hence there is a certain measure ofefficiency thus gained as they are reflected Within the glass and to ameasure heighten the brilliance of the copy.

Numeral 54 in Figure 7 indicates the display sheet which has a surface60 which 1s adhesive to glass. The sheet has the property of reflectingmost of the light falling upon 1t. It is also preferred that it disperseor diffuse the light althoA this is not essential in all cases. The mainmember of the sheet consists of a flexible body indicated by 61 whichmay be made of fabric as indicated in the view. Any other suitablematerial, however, may be used such as metallic foil or parchment. Theadhesive surface is preferably formed by a layer of soft rubberindicated by 65. Unvulcanized rubber serves Well for this purpose as itadheres firmly to glass yet may bepeeled ofl' without leaving any smudgeor detached particles. If the layer of adhesive is opaque then v itshould be of a light color so that reflection takes place at the surfaceof contact. If it is transparent then a layer of metallic foil asindicated by 62 is sealed in the body preferably in contact with thefabric and serves as the reflector. Another suitable method is to makethe fabric itself of bright metallic wires so that the light isdispersed from the surface of the Wire.

The term copy as used herein is to be understood as referring to anyWritten messa e.

In a generic sense the term display pattern as used herein includes anypattern o inscriptions, characters, figures, numerals, symbols,ornaments, designs, borders or signs, whether including but one of anysuch devices, or a number of any of such devices or any combination ofsuch devices when used as an intended visible portion of the displayaccording to the invention.

rlhe term translucent is used herein in its broadest sense as describingany body thru which radiation may pass 1n such quantities as to renderthe same luminous to the eye from any normal angle of view.

In my prior application Serial No. 526,344, certain features disclosedherein are claimed, and it is to be understood that the features claimedherein are improvements over said prior application.

Having thus described my invention, what I claim is:

l. In a changeable display sign, a body of light transmitting material,means to pass radiation therethru at an angle such that a materialpercentage thereof is reflected back into said body from a surface and asheet of translucent material having a surface thereof adhesive to saidsurface of said body positioned close to said surface of said body andso disposed that upon pressing portions of said sheet down onto saidsurface of said body a portion of the radiation incident upon saidsurface is dispersed and caused to leave said body thru said portionsthus rendering the same luminous to the eye.

2. In a-changeable display sign, a body of light transmitting material,means to pass radiation therethru at an angle such thatv a materialpercentage thereof is reflected back into said bod sheet of trans ucentmaterial having a surface thereof adhesive to said surface of said bodyso that upon being pressed together an intimate contact is formed andradiation from Within said body is caused to leave the same thru thecontact regions.

3. In a changeable display sign, a body of light transmitting material,means to pass radiation therethru at an angle such that a materialpercentage thereof is reflected back into said body from a surfacethereof, and a sheet of translucent' material secured at one edge tosaid surface and disposed so that it may be pressed closely to saidsurface of said body to provide a region of contact thru which radiationfrom within said body may escape from the same.

4. In a changeable display sign, a bod) of light transmitting material,means t'o pass radiation therethru at an angle such that a materialpercentage thereof is reflected back into said body from a surfacethereof, and a sheet of flexible material having a surface finished sothat upon being pressed down into intimate contact with a surface ofsaid body a portion of the radiation incident upon said surface of saidbody is dispersed and caused to leave said body thereby rendering theregions of contact luminous to the eye.

5. In pa double faced changeable sign, a sheet of light transmittingmaterial, means to pass radiation therethru at angles such as to bereflected between the opposite surfaces thereof, and sheets of flexibletranslucent material positioned on opposite surfaces thereof, thesurfaces of said sheets of flexible material closest to the surfaces ofsaid body being so finished that upon being pressed down onto said bodythey make intimate contact thereat and provide an exit for a port-ion ofthe radiation incident upon said contact surfaces. v

6. In a double faced changeable sign, a y sheet of light transmittingmaterial, means to pass radiation therethru at angles such as to bereflected between the opposite surfaces thereof, and sheets of flexibletranslucent material positioned on opposite sides thereof, the surfacesof said sheets of flexible material closest to the surfaces of said bodybeing adhesive to said body When pressed thereupon.

7. A sheet of light transmitting material, means t'o radiate rays oflight edgewise thru said sheet so that they are reflected back into saidsheet fromthe surfaces thereof, and a flexible sheet of materialpermeable to rays of light having a surface adhesive thereto disposednear to a surface of said sheet of from a surface thereof and a lighttransmitting material so that upon pressing portions of said flexiblesheet thereupon a path is provided for the escape of rays of lighttherefrom thus rendering such portions luminous.

8. A sheet of light transmitting material, means to radiate rays oflight edgewise thru said sheet so that they are reflected back into saidbody from a surface thereof, and a flexible sheet of material permeableto rays of light fastened at an edge thereof to said sheet of lighttransmitting material and having a surface adhesive to said lighttransmitting material so that upon being pressed there-\ upon the twounite to form a surface of contact thru which rays of light escape fromthe firsti said sheet thus rendering the areas of contact luminous tothe eye.

9. The method of writing luminous copy on a display sign including abody of light transmitting material having radiation transmittedtherethru and reflected back into the same from a surface thereof, whichconsists in positioning a sheet of light transmitting material having a.surface capable of making intimate contact with said surface of saidbody adjacent said surface of said body and pressing together portionsof the surfaces thereof thereby causing radiation to escape from saidbody thru said sheet.

10. VThe method of eradicating luminous copy in a sign on which copy hasbeen written according to claim 9 which consists in peeling said sheetoff of the said surface of the said body.

11. The method of vwriting copy on a display sign including a body oflight t-ransmitting material having radiation transmitted therethru andreflected back into said body from a surface thereof which consists inpositioning a sheet of light reflecting material having a surfacecapable of making intimate contact with said surface of said bodyadjacent said surface of said body and pressing together portions of thesurfaces thereof thereby dispersing the radiation incident upon the saidportions and causing radiation to escape from said body.

12. The method of eradicating luminous copy in a sign on which copy havebeen written according to claim 11 which consists in peeling said sheetoff of the said surface of the said body.

13. In a changeable display sign, a sheet of light transmittingmaterial, means to pass radiation therethru in such manner as to bereflected between opposite surfaces thereof, a flexible sheet ofmaterial positioned adjacent one of the surfaces thereof and visible asa display surface thru said sheetof light transmitting material, saidflexible sheet having a surface adhesive to said light transmittingmaterial whereby upon pressing portions of the two together theradiation incident upon those portions from within said sheet of lighttransmitting material is altered in its reflection as compared with thereflection from other portions of the surface of said light transmittingmaterial thus delineating to the eye a display pattern.

14. In a changeable display sign, a sheet of light transmittingmaterial, means to pass radiation therethru in such manner as to bereflected between opposite surfaces thereof, a flexible sheet ofmaterial positioned adjacent one of the surfaces thereof and visible asa display surface thru said sheet of light transmitting material, saidflexiblesheet having a surface adhesive to said light'transmittingmaterial and having light reflecting qualitiesv differing from the lightreflecting quality of the surface of said light transmitting materialwhereby upon pressing portions of the two together the radiationincident upon such portions is caused to change its angle of reflectionthereby passing thru said sheet of light transmitting material at anangle at which it escapes therefrom and becomes visible to the eye.

15, In a changeable display sign, a sheet of light ytransmittingmaterial, means to pass radiation therethru in such manner as to bereflected between opposite surfaces thereof, a flexible sheet ofmaterial positioned adjacent one of the surfaces thereof, said ilexiblesheet having its near surface so finished as to make intimate contactwith the surface of said light transmitting material when portions ofthe two are pressed together and to disperse the radiation incident`upon the surface of contact so established whereby portions of suchradiation are caused to leave the sheet of light transmitting materialand delineate a display pattern to the eye.

Signed at Chicago, Ill., this 3rd day of April, 1931. v

FRED HOTCHNER.

